Device for adjustment of level of inclination of back part of motor vehicle seat

ABSTRACT

The present invention relates to a device for adjustment of the level of inclination of the back part of a motor vehicle seat having a device part ( 2 ) connected to the seat part and a device part ( 3 ) connected to the backrest, which can be pivoted opposite to each other about a pivot axis ( 14 ), wherein both device parts ( 2, 3 ) have parts of gearings ( 4, 5 ) forming a swash mechanism, which roll over each other under the influence of cam means ( 11 ) that can be rotated about a pivot axis ( 14 ). The drive of the cam means ( 11 ) is provided via a two-part carrier, comprised of a metal carrier boss ( 17 ) and a metal carrier plate ( 18 ) non-rotatingly connected therewith. The carrier boss ( 17 ) has a collar ( 17.2 ) for axial bracketing of the device parts ( 2, 3 ) on one side of the device for adjustment of the level of inclination ( 1 ). The object is to configure this type of device for adjustment of the level of inclination, so that no longer requires an additional locking ring for axial bilateral bracketing of the device parts ( 2, 3 ). The solution resides in the fact that the carrier plate ( 18 ) is fastened axially to the carrier boss ( 17 ) on the other side of the device for adjustment of the level of inclination ( 1 ) for completion of the bracketing of the device parts ( 2, 3 ).

The present invention relates to a device for adjustment of the level ofinclination of the back part of a motor vehicle seat in accordance withthe superordinate concept of claim 1.

This type of device for adjustment of the level of inclination iswell-known from DE 43 03 819 A1. Its device parts have an inner and anouter gearing, which are manufactured by forming using cutouts of themetal plate of the device parts. When this is done, the outer gearinghas a number of teeth that is at least one less than the inner gearingand one of the device parts is supported on cam means that are rotatableabout an pivot axis. By rotating said cam about the pivot axis of thedevice for adjustment of level of inclination, the inner gearing of theone device part over the outer gearing of the other device part. In thisfashion, a pivoting of the device part fixed to the seat backcorresponding to the gearing number difference is attained relative tothe device part fixed to the seat part. The advantage of this and other,in principal identically constructed adjustment devices resides in thefact that they make possible a continuous adjustment, even underconditions of high loading.

In the event of impact, there can be a slippage of the gearing of thetwo device parts due to bending away of the parts due to the very high,axially acting forces. In order to prevent this, an axial bracketing ofthe two device parts is provided. Mounting plates are included, whereinone mounting plate is affixed to one of the device parts and the zonallyoverlaps the other device part. In the case of the device for adjustmentof the level of inclination according to the aforementioned DE 43 03 819A1 the two device parts are in addition axially secured in the zone ofthe pivot axis by a metal carrier boss. In addition, the carrier bosshas a collar, which abuts on one of the device parts, whilst on theother side of the other device part, a lock washer affixed to thecarrier boss provides the axial bracketing.

DE 101 34 355 A1 discloses a device for adjustment of the level ofinclination, wherein the carrier, comprised of a carrier plate and acarrier boss is formed in one piece. Here, the carrier plate on the oneside of the device for adjustment of the level of inclination providesthe axial securing, while on the other side a locking ring is affixed onthe carrier boss.

The object of the present invention is to provide a generic device foradjustment of the level of inclination, wherein a two-part carriercomprised of a carrier boss and a carrier plate for axial bracketing ofthe two device parts, eliminates the need for an additional lockingring.

This object is achieved according to the invention with a device foradjustment of the level of inclination having the characteristics ofclaim 1.

In the inventive solution, the carrier disk is used, in addition to itsfunction in introducing an adjustment movement in the cam means, alsosimultaneously to axially bracket the device for adjustment of the levelof inclination, in which it is affixed axially to the carrier boss onside opposite to the collar of the device for adjustment of the level ofinclination. Because both parts are made of metal, this bracketing isvery stabil. In addition, this “clamping” increases the safety andreliability of the device for adjustment of the level of inclinationvis-à-vis the conventional mounting plates clamping the device parts onthe periphery of the gearing, against unintended “opening” in the eventof impact.

Because of the two-part configuration of the carrier, it isadvantageously possible to realize the carrier plate as a die-cut part.This also has a cost-reducing effect. In addition, with relativelyminimal plate thickness adequate strength in the carrier is achieved invirtue of the cold forming process used.

In order to obtain a seating of the carrier plate that resists rotationon the carrier boss, the carrier plate is pushed onto a projectingflange of the carrier boss having an non-circular section. The axialfixation of the carrier plate on the carrier box realized in that atleast partial zones of the projecting flange end abut force-lockingly onthe outer side of the carrier plate. This force-locking connection can,for example, be obtained by cupping or spreading or even by clenchingthe end of the flange.

Other advantageous configurations of the invention issue from the othersubordinate claims.

The invention will be more completely described in the following usingan exemplary embodiment. The relevant drawing shows in:

FIG. 1 The structural parts of a device for adjustment of the level ofinclination according to the invention in an exploded perspectiverepresentation;

FIG. 2 is a representation according to FIG. 1 from another viewingdirection;

FIG. 3 is a representation of the assembled device for adjustment of thelevel of inclination;

FIG. 4 is a perspective view onto the representation according to FIG. 3opposite to the direction of the arrow A with the cover cap removed;

FIG. 5 is a view onto the representation according to FIG. 3 in thedirection of the arrow A, and

FIG. 6 is a section B-B according to FIG. 5.

The device for adjustment of the level of inclination 1 represented inthe drawing is part of a motor vehicle (not shown) having a seat partand a backrest, wherein the backrest in its inclination can be adjustedrelative to the seat part by means of the device for adjustment of thelevel of inclination. In addition, the device for adjustment of thelevel of inclination 1 has a device part 2 affixed to the seat part anda device part 3 affixed to the backrest. Both device parts 2, 3 aresheet steel plates, wherein the device part 2 has an outer gearing 4stamped out of the plate and the device part 3 has an inner gearing 5stamped out of the plate. The outer gearing 4 in the same module has agearing that has one less tooth than the inner gearing 5. In theassembled device for adjustment of the level of inclination 1 the outergearing 4 and the inner gearing 5 enmesh together. The device part 3has, in addition, a passage 6 that is stamped concentrically with theinner gearing 5 and which as a circular passage opening 7. An innerbearing ring can be pushed onto the passage 6. The device part 2 alsohas a circular passage opening 9 arranged concentrically with the outergearing 4, into which an outer bearing ring 10 can be inserted.

The bearing rings 8 and 10 are sued for mounting of cams 11. These arecomprised of an eccentric collar 12 and two identical wedge segments 13arranged in mirror-image. In the assembled state, the eccentric collar12 is pushed onto the inner mounting ring 8, the wedge segments 13 liewith their inner sides 13.1 on the eccentric collar 12 and the outersides 13.2 of the wedge segments 13 abut on the inner side 10.1 of theouter bearing ring 10. Because of this intermediation of the cam means11 between the two device parts 2 and 3, there is an eccentricity e (seeFIGS. 3 and 6) between the middle axes of the passage opening 7 of thedevice part 3 and the middle axis 16 of the passage opening 9 of thedevice part 2 (see FIGS. 3 and 6) forming the pivot axis 14 of thedevice for adjustment of the level of inclination 1. This eccentricity eassures that the outer gearing 4 is urged, in extension of the directionof the eccentricity e, into the inner gearing 5 of the device part 3. Inorder to embody this interlocking of the outer gearing 4 and the innergearing 5 and the to bearing of the two device parts 2 and 3 free ofplay, the wedge segments 13 are biased with springs so that they areurged away from each other peripherally on the eccentric collar 12 inthe sense of an increase of the eccentricity e. In the present exemplaryembodiment an omega spring 15 is provided as the spring means, whosemember 15.1 deflected at right angles abut on the facing sides 13.3 ofthe wedge segments 13 and urge these, as described, apart.

The aforedescribed arrangement assures that the device for adjustment ofthe level of inclination 1 is arrested without play in any setinclination of the backrest, because the forces acting from the backrestare absorbed radially by the wedge segments 13; thus, no actuatingforces are exerted on them. The tension induced by the omega spring 15on the wedge segments 13 can be relieved only by the tangential forcesacting on the wedge segments 13. A two-part carrier, comprised of acarrier boss 17 and a carrier plate 18, is provided for introducing saidarresting movement on the cam means 11. The carrier is described ingreater detail in the following.

Both the carrier boss 17 and the carrier plate 18 are made of metal.Here, the carrier boss 17 is a die cast part or forged part and thecarrier plate 18 is executed as a plate metal stamped part. The carrierboss 17 has a cylindrical central section 17.1, a collar 17.2, whichdiametrically overhangs the cylindrical central section 17.1, and aflange 17.3, diametrically somewhat smaller, having a non-circularcross-section; that is, a cross-section for transferring a torque. Inthe installed state the central section 17.1 protrudes through thepassage opening 7 of the passage 6 with little radial clearance, whileits collar 17.2 abuts on the device part 3 from the outside. On theother side of the device for adjustment of the level of inclination 1,the carrier plate 18 is pushed onto the flange 17.3 of the carrier boss17. For this purpose the carrier plate 18 has a central opening 18.1with the same non-circular cross-section as the flange 17.3. Afterpushing on the carrier plate 18 onto the flange 17.3 the carrier plate18 is accordingly non-rotational on the carrier boss 17. Material of theflange 17.3 is urged onto the carrier disk 18 for axial fixation of thecarrier disk 18 on the carrier boss 17, so that projecting barbs 19 arecreated (as shown in FIG. 6) relative to the cross-section of thecentral opening 18.1 of the carrier plate 18. The carrier boss 17 andthe carrier plate 18 are thus clenched together by the barbs 19.

It is also very clear from the representation according to FIG. 6 thatthere is an axial bracketing of the two device parts 2 and 3 in additionto the mounting plates (not shown in the representation) by the collar17.2 of the carrier boss 17 abutting at the device part 3 and thecarrier plate 18 on the other side of the adjusting device 1 abutting atdevice part 2. These mounting plates are welded to the device parts 2and 3 using a weld bridge 20 and bridge the respective other device part2 or 3 zonally at the periphery of the inner gearing 5 or the outergearing 4.

The carrier plate 18 has two expressed carrier fingers 21. In assembleddevice for adjustment of the level of inclination 1, these carrierfingers 21 each engage into an interspace between the eccentric collar12 and the outer mounting ring 10. Here, their facial surfaces 21.1 lieperipherally separated from the faces 13.4 of the wedge segments 13facing away from the omega spring 15. This peripheral spacing betweenthe faces 21.1 and 13.4 is provided, in order that the adjusting forceof the omega spring 15 on the wedge segments 13 is not impaired. Alongwith the carrier fingers 21, the carrier plate 18 has openings 22 and23. The opening 22 serves as the passage for the member 15.1 of theomega spring 15, while the openings 23 is used for snapping in a plasticcover cap 24 on the carrier plate 18. For this purpose snap nubs 25 areprovided on the cover cap 24, which can be pushed into the openings 23and can be locked behind same. A spring tab 26 is provided on the covercap 24 as an additional locking means, said tab passing through theopening 22 of the carrier plate and locks behind same.

The cover cap 24 is used for coving the omega spring 15 and the carrierplate 18; in particular, however, for covering the open articulationzone of the device for adjustment of the level of inclination 1, inorder to protect it from fouling, especially at the time of painting.The cover cap 24 has a fastening means comprised of four tabs 27, whichcan be inserted form-lockingly into a central recess 28 in the carrierboss 17. When this is done, the inner surfaces of the tabs 27 form acircular cross-section 29; in the case of this exemplary embodiment, asquare cross-section, for form-lockingly receiving a driver rod (notshown) (see FIG. 5). This driver rod is used for introducing a torqueinto the device for adjustment of the level of inclination 1 and can bepart of a hand wheel or a motor-driven shaft. Pawls 27.1 are provided atthe ends of the tabs 27 of the cover cap 24 and project radiallyoutwards. These interlock after pushing the tabs 27 through the carrierboss 17, behind its collar 17.2, as shown in FIG. 6. With a built-indriver rod, the tabs 17 can no longer yield radially, whereby thelocking between the pawls 27.1 and the collar 17.2 is assured.

The embodiment represented of the cover cap 24 assures, together withthe carrier boss 17, their secure axial hold on the device foradjustment of the level of inclination 1 and an additional axialbracketing of the two device parts 2 and 3. In addition, the plastictabs 27 arranged between the driver rod and the carrier boss 17 preventa metal-metal contact between the driver rod and the carrier boss 17,whereby undesirable rattling noise can be prevented.

For operating the device for adjustment of the level of inclination 1, atorque is transferred to the carrier plate 18 using the driver rod,driven by a hand wheel or a drive motor unit, the tabs 27 of the sleeveof the cover cap 24 and the carrier plate 17. In this way, the face 21.1of one of its carrier fingers 21, depending in which direction it isrotated, comes to lie on the face 13.4 of the wedge segment 13associated with this carrier finger 21. With further rotation of thecarrier plate 18, effort is applied against the force of the omegaspring 15; in other words, the tensioning of the wedge segments 13between the eccentric collar 12 and the outer bearing ring 10 isrelieved, so that a radial play is created for the moving of the devicefor adjustment of the level of inclination 1. Upon further operation bythe driver rod, the wedge segments 13 rotate together with the eccentriccollar 12 about the pivot axis 14. Because of this rotary movement ofthe cam 11, the direction of eccentricity e is extended and thus alsothe engagement point of the outer gearing 4 in the inner gearing 5.Accordingly a rolling movement of the outer gearing 4 on the innergearing 5 occurs and the device part 3 pivots on the stationary devicepart 2. As soon as the torque transfer into the device for adjustment ofthe level of inclination 1 via the driver rod is ended, the omega spring15 again urges the wedge segments 13 into their starting position; inother words, the eccentricity e is again increased, whereby the radialclearance required for the adjustment movement is eliminated and thebackrest is again arrested.

1. A device for adjustment of the level of inclination of the back partof a motor vehicle seat having a device part (2) affixed to the seatpart and a device part (3) affixed to the backrest, which can be pivotedopposite to each other about a pivot axis (14), whereby both deviceparts (2, 3) have parts of gearings (4, 5) forming a swash mechanism,which roll over each other under the influence of cams (11) that arerotatable about a pivot axis (14), wherein the drive of the cams (11) isprovided via a two-part carrier comprised of a metal carrier boss (17)and, non-rotatingly connected to it, a metal carrier plate (18) havingat least one carrier finger (21) for rotary carrying of the cam means(11), wherein the carrier pawl (17) has a central recess (28) forreceiving a driver rod, and a collar (17.2) for axial bracketing of thedevice parts (2, 3) on one side of the device for adjustment of thelevel of inclination (1), characterized in that the carrier plate (18)is affixed axially on the carrier pawl (17) on the other side of thedevice for adjustment of the level of inclination (1) for completing thebracketing of the device parts (2, 3).
 2. The device for adjustment ofthe level of inclination according to claim 1, wherein the carrier plate(18) manufactured as a die cut plate part.
 3. The device for adjustmentof the level of inclination according to claim 1, wherein the carrierplate (18) is seated on a protruding flange (17.3) of the carrier boss(17) with non-circular profile and the projecting flange end abuts atleast in partial zones force-lockingly on the carrier plate (18).
 4. Thedevice for adjustment of the level of inclination according to claim 2,wherein the carrier plate (18) is seated on a protruding flange (17.3)of the carrier boss (17) with non-circular profile and the projectingflange end abuts at least in partial zones force-lockingly on thecarrier plate (18).
 5. The device for adjustment of the level ofinclination according to claim 1, wherein a plastic cover cap (24) isprovided for covering the articulation zone and the recess (28) of thecarrier boss (17) has a larger cross-section than the driver rod,wherein the cover cap (24) has a connector formed from tabs (27), whichcan be positively inserted into the receptacle (28) of the carrier boss(17) and the inner surfaces of the tabs (27) form a non-circularcross-section (29) for positively receiving the driver rod.
 6. Thedevice for adjustment of the level of inclination according to claim 5,wherein the ends of the tabs (27) are provided with radially outwardlyprojecting pawls (27.1), which lock on the opposing side of the covercap (24) behind a component of the device for adjustment of the level ofinclination (1).
 7. The device for adjustment of the level ofinclination according to claim 5, wherein the carrier plate (18) hasopenings (23) and the cover cap (24) has locking nubs (25), which can beinserted into the openings (23) and can be locked behind same.